1. Field of Invention
This invention relates to wireless communications systems. Specifically, the present invention relates systems and methods for mitigating high wireless busy hour call attempts (BHCA) due to wireline congestion.
2. Description of the Related Art
Wireless communications systems are used in a variety of demanding applications including search and rescue and business applications. Such applications require reliable communications systems that can efficiently route calls to a wireline network during the busiest hour of the day while using a minimum amount of wireless network resources.
Wireless telecommunications systems are characterized by a plurality of mobile stations (e.g. fixed wireless phones or mobile phones) in communication with one or more base stations. A signal transmitted by a mobile station is received by a base station and relayed to a base station controller (BSC). The BSC in-turn routes the signal to another base station, mobile switching center (MSC), or directly to a public switched telephone network (PSTN). Similarly, a signal may be transmitted from the PSTN to a mobile station via a base station and an MSC. The PSTN is often called the landline network or the wireline network. In a wireline network, calls are routed via wire over land rather than over air via radio links.
Each base station governs a limited geographic region called a cell. Typically, the coverage area of a wireless telecommunications system is divided into multiple cells. When a mobile station moves from a first cell to a second cell, a handoff is performed to assign new system resources associated with the second cell to the mobile station.
The wireless network must maintain sufficient resources to accommodate periods of peak telephone usage. Landline congestion often taxes wireless resources. For example, a call attempted via a wireless network to a telephone on the wireline network may require several attempts before the call is connected. The average number of attempts required to complete a call between the wireless network and the wireline network during the busiest hour of the day is known as the busy hour call attempts (BHCA). Typically, a wireless network must have sufficient wireless resources, i.e. bandwidth, software, and hardware, to accommodate the requisite BHCA for call completion.
In telephone markets such as the Indian market or the Sri Lankan market, wireline congestion is particularly problematic. In such markets, the wireless infrastructure must often accommodate as many as 8 BHCA per wireless service subscriber. Typically, to accommodate the requisite call attempts additional resources such as access/traffic channels and associated software and hardware are added to the wireless network. The additional resources are expensive and often require additional expensive engineering and installation work.
The wireless network from which a call originates must Provision resources for each busy call due to wireline congestion. The Provisionary of resources is extremely inefficient and costly. In a market such as the Indian market, the wireless network infrastructure capacity is greatly expanded to accommodate the redundant redialing required to establish a call to a wireline telephone during periods of wireline congestion.
Hence, a need exists in the art for a system and method that reduces the requisite additional wireless infrastructure needed to handle high BHCA and that virtually eliminates the redundant redialing required to establish a call to a wireline telephone during periods of wireline congestion.
The need in the art is addressed by the system for reducing wireless telecommunications network resources required to successfully route calls to a wireline network of the present invention. The system includes a first mechanism for routing a call originated from a wireless party connected to a wireless network to a wireline party connected to a wireline network. A second mechanism determines if the wireline network is congested in response to the mechanism for routing and provides a signal in response thereto. A third mechanism selectively queues the call in response to the signal. A fourth mechanism connects the wireless party to the wireline party when the call reaches a front of the queue and the wireline network can accept the call.
In a specific embodiment, the first mechanism for routing the call includes a mobile switching center in communication with a base station or base station controller. The base station or base station controller communicates with a mobile station associated with the wireless party. The second mechanism for determining if the wireline network is congested includes a mechanism for monitoring to determine if the call is completed and indicating that the network is congested via the signal if the call is not completed. The third mechanism for selectively queuing the call includes software running on the mobile switching center and/or the base station controller for placing the call on the queue. The software may also run on an external application processor. The fourth mechanism for connecting the wireless party includes a mechanism for monitoring when the wireline party answers with respect to when the wireless party is notified that the call is about to be completed. The fourth mechanism further includes a mechanism for notifying the wireline party that the wireless party will connect shortly if the wireline party answers the call before the wireless party is notified that the call is to be completed via the fourth mechanism. The fourth mechanism also includes a mechanism for informing the wireline party that the wireless party is unavailable if the wireless party cannot be notified or contacted by the mechanism for connecting. In the illustrative embodiment, the system includes an additional mechanism for exchanging recorded messages between the wireless party and the wireline party.
The novel design of the present invention is facilitated by the use of call queuing software running on a mobile switching center or application processor for implementing the first, second, third, and fourth mechanisms and selectively queuing calls in the face of wireline congestion. The selective queuing of calls reduces the need for constant redialing by a wireless party, which eliminates redundant use of wireless network resources to accommodate the redialing. As a result, substantial savings are achieved in terms of wireless infrastructure costs.